Operation method of a communication node in network

ABSTRACT

An operation method of a first communication node comprises: receiving a first frame from a second communication node; obtaining a destination address of the first frame; and transmitting a second frame including an indicator for indicating an occurrence of an error in the first frame to a communication node corresponding to a source address of the first frame, when a port corresponding to the destination address does not exist in a routing table.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Korean PatentApplication No. 10-2016-0048930, filed on Apr. 21, 2016 in the KoreanIntellectual Property Office (KIPO), the entirety of which isincorporated by reference as if fully set forth herein.

TECHNICAL FIELD

The present disclosure relates to an operation method of a communicationnode in a network, and more specifically, to an operation method forresolving outing errors occurring when a destination address of a frametransmitted by a communication node has an error.

BACKGROUND

Electronic devices installed in a vehicle have been increasedsignificantly in their number and variety along with recentdigitalization of vehicle parts. Generally, electronic devices may beused throughout the vehicle, such as in a power train control system(e.g., an engine control system, an automatic transmission controlsystem, or the like), a body control system (e.g., a body electronicequipment control system, a convenience apparatus control system, a lampcontrol system, or the like), a chassis control system (e.g., a steeringapparatus control system, a brake control system, a suspension controlsystem, or the like), a vehicle network (e.g., a controller area network(CAN), a FlexRay-based network, a media oriented system transport(MOST)-based network, or the like), a multimedia system (e.g., anavigation apparatus system, a telematics system, an infotainmentsystem, or the like), and so forth.

The electronic devices used in each of these systems are connected viathe vehicle network, which supports functions of the electronic devices.For instance, the CAN may support a transmission rate of up to 1 Mbpsand support automatic retransmission of colliding messages, errordetection based on a cycle redundancy interface (CRC), or the like. TheFlexRay-based network may support a transmission rate of up to 10 Mbpsand support simultaneous transmission of data through two channels,synchronous data transmission, or the like. The MOST-based network is acommunication network for high-quality multimedia, which may support atransmission rate of up to 150 Mbps.

The telematics system and the infotainment system, like most enhancedsafety systems of a vehicle do, require higher transmission rates andsystem expandability. However, the CAN, FlexRay-based network, and thelike may not sufficiently support such requirements. The MOST basednetwork, in particular, may support a higher transmission rate than theCAN or the FlexRay-based network, However, applying the MOST-basednetwork to vehicle networks can be costly. Due to these limitations, anEthernet-based network is often utilized as a vehicle network. TheEthernet-based network may support bi-directional communication throughone pair of windings and may support a transmission rate of up to 10Gbps. The Ethernet-based vehicle network may include a plurality ofcommunication nodes. The communication node may be a gateway, a switch(or bridge), an end node. or the like.

The Ethernet-based vehicle network may comprise a plurality ofcommunication nodes. A communication node may be a gateway, a switch (ora bridge), an end node, or the like. The plurality of communicationnodes constituting the vehicle network can transmit and receive framesto each other.

In the IEEE 802.1Qcc standard, when a communication node operating as aswitch or a bridge receives a frame, it may decide a routing path byreferring to the destination MAC address information and the internalrouting table without a separate error check on the frame. Then, thecommunication node may configure a port (for example, a transmissionport) used for transmission of the frame based on the determined routingpath, and transmit the frame through the configured port. However, ifthe destination MAC address of the frame includes an error, thecommunication node may have a problem that the frame is transmitted to awrong destination. That is, the communication node may generate an errorin the routing process of the frame due to the error of the destinationMAC address of the frame. In addition, since the communication nodemaintains the frame transmission scheme currently used even when suchthe error occurs, there is a problem that errors occur continuously inthe routing process of the continuous frames.

SUMMARY

The present disclosure provides methods for resolving a frame routingerror caused by an error in a destination address of a frame at acommunication node constituting a vehicle network.

In accordance with embodiments of the present disclosure, an operationmethod of a first communication node in an Ethernet-based vehiclenetwork may comprise: receiving a first frame from a secondcommunication node; obtaining a destination address of the first frame;and transmitting a second frame including an indicator for indicating anoccurrence of an error in the first frame to a communication nodecorresponding to a source address of the first frame, when a portcorresponding to the destination address does not exist in a routingtable.

The destination address may be obtained from a medium access control(MAC) header of the first frame.

The operation method may further comprise discarding the first frame.

The second frame may further include an indicator for instructingcorrection of the error in the first frame.

The second frame may further include an indicator for instructingtransmission of an error-corrected frame in which the error in the firstframe is corrected.

The operation method may further comprise receiving a third frame fromthe second communication node; performing an error check operation onthe third frame; obtaining a destination address of the third frame whenthe third frame has no error; and transmitting he third frame through aport corresponding to the destination address of the third frame basedon the routing table.

The first communication node may be a switch or a bridge, and the secondcommunication node may be an end node connected to the firstcommunication node.

The first communication node may support a cut-through frame routingscheme.

According to another exemplary embodiment of the present disclosure, anoperation method of a first communication node in an Ethernet-basedvehicle network may comprise: receiving a first frame from a secondcommunication node; obtaining a destination address of the first frame;transmitting the first frame through a port corresponding to thedestination address based on a routing table of the first communicationnode; receiving a second frame including an indicator indicating anoccurrence of an error in the first frame from a third communicationnode receiving the first frame; and transmitting the second frame to acommunication node corresponding to a source address of the first frame.

The destination address may be obtained from a medium access control(MAC) header of the first frame.

The second frame may further include an indicator for instructingcorrection of the error in the first frame.

The second frame may further include an indicator for instructingtransmission of an error-corrected frame in which the error in the firstframe is corrected.

The operation method may further comprise receiving a third frame fromthe third communication node, the third frame including an indicatorrequesting to perform the error check operation; receiving a fourthframe from the second communication node; performing the error checkoperation on the fourth frame; obtaining a destination address of thefourth frame when the fourth frame has no error; and transmitting thefourth frame through a port corresponding to the destination address ofthe fourth frame based on the routing table.

The first communication node may be a switch or a bridge, and the secondcommunication node and the third communication node may be end nodesconnected to the first communication node.

The first communication node may support a cut-through frame routingscheme.

According to another exemplary embodiment of the present disclosure, anoperation method of a first communication node in an Ethernet-basedvehicle network may comprise: receiving a first frame from a secondcommunication node; performing an error check operation on the firstframe; generating a second frame including an indicator indicating anoccurrence of an error in the first frame when the first frame has theerror; and transmitting the second frame to a communication nodecorresponding to a source address of the first frame.

The first frame may be a frame on which the second node does not performthe error check operation.

The error in the first frame may be identified by performing a cyclicredundancy check on the first frame based on a frame check sequence(FCS) included in a FCS field of the first frame.

The operation method may further comprise generating a third frameincluding an indicator requesting to perform the error check operation;and transmitting the third frame to the second communication node.

The first communication node may be an end node connected to the secondcommunication node, and the second communication node may be a switch ora bridge.

The second communication node may support a cut-through frame routingscheme.

According to the embodiments of the present disclosure, in anEthernet-based vehicle network, a communication node using a cut-throughframe routing scheme defined in the IEEE 801.1Qcc standard is able tostop the cut-through frame routing scheme, when a routing error of aframe occurs due to an error in a destination MAC address of the frame.In addition, the communication node using the cut-through frame routingscheme can reduce a load on the vehicle network by preventingunnecessary frame transmission and reception caused by the error of thedestination MAC address of the frame.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present disclosure will become more apparent bydescribing in detail forms of the present disclosure with reference tothe accompanying drawings, in which:

FIG. 1 is a diagram showing a vehicle network topology according toembodiments of the present disclosure;

FIG. 2 is a diagram showing a communication node constituting a vehiclenetwork according to embodiments of the present disclosure;

FIG. 3 is a sequence chart illustrating an embodiment of an operationmethod of a communication node constituting an Ethernet-based vehiclenetwork;

FIG. 4 is a conceptual diagram illustrating an embodiment of a frameused in an

Ethernet-based vehicle network;

FIG. 5 is a sequence chart illustrating another embodiment of anoperation method of a communication node constituting an Ethernet-basedvehicle network;

FIG. 6 is a sequence chart illustrating an operation method of a firstcommunication. node in an Ethernet-based vehicle network according to anembodiment of the present disclosure; and

FIG. 7 is a sequence chart illustrating an operation method of a firstcommunication node in an Ethernet-based vehicle network according toanother embodiment of the present disclosure.

It should be understood that the above-referenced drawings are notnecessarily to scale, presenting a somewhat simplified representation ofvarious preferred features illustrative of the basic principles of thedisclosure. The specific design features of the present disclosure,including, for example, specific dimensions, orientations, locations,and shapes, will be determined in part by the particular intendedapplication and use environment.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the accompanying drawings. As those skilled inthe art would realize, the described embodiments may be modified invarious different ways, all without departing from the spirit or scopeof the present disclosure. Further, throughout the specification, likereference numerals refer to like elements.

The terminology used herein is for the purpose of describing particularforms only and is not intended to be limiting of the disclosure. As usedherein, the singular forms “a,” “an,” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

It is understood that the term “vehicle” or “vehicular” or other similarterm as used herein is inclusive of motor vehicles in general such aspassenger automobiles including sports utility vehicles (SUV), buses,trucks, various commercial vehicles, watercraft including a variety ofboats and ships, aircraft, and the like, and includes hybrid vehicles,electric vehicles, combustion, plug-in hybrid electric vehicles,hydrogen-powered vehicles and other alternative fuel vehicles (e.g.fuels derived from resources other than petroleum).

Although forms are described herein as using a plurality of units toperform the exemplary process, it is understood that the exemplaryprocesses may also be performed by one or plurality of modules.Additionally, it is understood that a controller/control unit mayperform one or more of the processes described further below, and theterm controller /control unit refers to a hardware device that includesa memory and a processor. The memory is configured to store the modules,and the processor is specifically configured to execute said modules toperform one or more processes which are described further below.Moreover, it is understood that the units or modules described hereinmay embody a controller/control unit for controlling operation of theunit or module.

Furthermore, a control logic of the present disclosure may be embodiedas non-transitory computer readable media on a computer readable mediumcontaining executable program instructions executed by a processor,controller/control unit or the like. Examples of the computer readablemediums include, but are not limited to, read-only memory (ROM), randomaccess memory (RAM), compact disc (CD)-ROMs, magnetic tapes, floppydisks, flash drives, smart cards and optical data storage devices. Thecomputer readable recording medium can also be distributed in networkcoupled computer systems so that the computer readable media is storedand executed in a distributed fashion, e.g., by a telematics server or aController Area Network (CAN).

Since the present disclosure may be variously modified and have severalforms, specific embodiments will be shown in the accompanying drawingsand be described in detail in the detailed description. It should beunderstood, however, that it is not intended to limit the presentdisclosure to the specific embodiments but, on the contrary, the presentdisclosure is to cover all modifications and alternatives falling withinthe spirit and scope of the present disclosure.

Relational terms such as first, second, and the like may be used fordescribing various elements, but the elements should not he limited bythe terms. These terms are only used to distinguish one element fromanother. For example, a first component may be named a second componentwithout being departed from the scope of the present disclosure and thesecond component may also be similarly named the first component. Theterm “and/or” means any one or a combination of a plurality of relatedand described items.

When it is mentioned that a certain component is “coupled with” or“connected with” another component, it should he understood that thecertain component is directly “coupled with” or “connected with” to theother component or a further component may he located therebetween. Incontrast, when it is mentioned that a certain component is “directlycoupled with” or “directly connected with” another component, it will beunderstood that a further component is not located therebetween.

Unless specifically stated or obvious from context, as used herein, theterm “about” is understood as within a range of normal tolerance in theart, for example within 2. standard deviations of the mean. “About” canbe understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%,0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear fromthe context, all numerical values provided herein are modified by theterm “about.”

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. Termssuch as terms that are generally used and have been in dictionariesshould be construed as having meanings matched with contextual meaningsin the art. In this description, unless defined clearly, terms are notideally, excessively construed as formal meanings.

Hereinafter, forms of the present disclosure will be described in detailwith reference to the accompanying drawings. in describing thedisclosure, to facilitate the entire understanding of the disclosure,like numbers refer to like elements throughout the description of thefigures and the repetitive description thereof will be omitted.

FIG. 1 is a diagram showing a vehicle network topology according to anexemplary embodiment of the present disclosure.

As shown in FIG. 1, a communication node included in the vehicle networkmay be a gateway, a switch (or bridge), or an end node. The gateway 100may be connected with at least one switch 110, 110-1, 110-2, 120, and130 and may be configured to connect different networks. For example,the gateway 100 may support connection between a switch which supports acontroller area network (CAN) (e.g., FlexRay, media oriented systemtransport (MOST), or local interconnect network (LIN)) protocol and aswitch which supports an Ethernet protocol. Each of the switches 110,110-1, 110-2, 120, and 130 may be connected to at least one of end nodes111, 112, 113, 121, 122, 123, 131, 132, and 133. Each of the switches110, 110-1, 110-2, 120, and 130 may interconnect the end nodes 111, 112,113, 121, 122, 123, 131, 132, and 133, and control at least one of endnodes 111, 112, 113, 121, 122, 123, 131, 132, and 133 connected to theswitch.

The end nodes 111, 112, 113, 121, 122, 123, 131, 132, and 133 mayinclude an electronic control unit (ECU) configured to control varioustypes of devices mounted within a vehicle. For example, the end nodes111, 112, 113, 121, 122, 123, 131, 132, and 133 may include the ECUincluded in an infotainment device (e.g., a display device, a navigationdevice, and an around view monitoring device).

The communication nodes (e.g., a gateway, a switch, an end node, or thelike) included in vehicle network may be connected in a star topology, abus topology, a ring topology, a tree topology, a mesh topology, or thelike. In addition, the communication nodes of the vehicle network maysupport the CAN protocol, the FlexRay protocol, the MOST protocol, theLIN protocol, or the Ethernet protocol. Embodiments of the presentdisclosure may be applied to the foregoing network topologies. Thenetwork topology to which forms of the present disclosure may be appliedis not limited thereto and may be configured in various ways.

FIG. 2 is a diagram showing a communication node constituting a vehiclenetwork according to embodiments of the present disclosure. Notably, thevarious methods discussed below may be executed by a controller having aprocessor and a memory.

As shown in FIG. 2, a communication node 200 of a network may include aphysical (PHY) layer 210 and a controller 220. In addition, thecommunication node 200 may further include a regulator (not shown) forsupplying power. In particular, the controller 220 may be implemented toinclude a medium access control (MAC) layer. The PHY layer 210 may beconfigured to receive or transmit signals from or to anothercommunication node. The controller 220 may be configured to control thePHY layer 210 and perform various functions (e.g., an infotainmentfunction, or the like.). The PHY layer 210 and the controller 220 may beimplemented as one system on chip (SoC), or alternatively may beimplemented as separate chips.

Furthermore, the PHY layer 210 and the controller 220 may be connectedvia a media independent interface (MII) 230. The MII 230 may include aninterface defined in the IEEE 802.3 and may include a data interface anda management interface between the PHY layer 210 and the controller 220.One of a reduced MII (RMII), a gigabit MII (GMII), a reduced GMII(RGMII), a serial GMII (SGMII), a 10 GMII (XGMII) may be used instead ofthe MII 230, A data interface may include a transmission channel and areception channel, each of which may have an independent clock, data,and a control signal. The management interface may include a two-signalinterface, one signal for the clock and one signal for the data.

Particularly, the PHY layer 210 may include a PHY layer interface 211, aPHY layer processor 212, and a PHY layer memory 213. The configurationof the PHY layer 210 is not limited thereto, and the PHY layer 210 maybe configured in various ways. The PHY layer interface 211 may beconfigured to transmit a signal received from the controller 220 to thePHY layer processor 212 and transmit a signal received from the PHYlayer processor 212 to the controller 220. The PHY layer processor 212may be configured to execute operations of the PHY layer interface 211and the PHY layer memory 213. The PHY layer processor 212 ay beconfigured to modulate a signal to be transmitted or demodulate areceived signal. The PHY layer processor 212 may be configured tocontrol the PHY layer memory 213 to input or output a signal. The PHYlayer memory 213 may be configured to store the received signal andoutput the stored signal based on a request from the PHY layer processor212.

The controller 220 may be configured to monitor and control the PHYlayer 210 using the Mil 230. The controller 220 may include a controllerinterface 221, a controller processor 222, a main memory 223, and a submemory 224. The configuration of the controller 20 is riot limitedthereto, and the controller 220 may be configured in various ways. Thecontroller interface 221 may be configured to receive a signal from thePHY layer 210 (e.g., the PHY layer interface 211) or an upper layer (notshown), transmit the received signal to the controller processor 222,and transmit the signal received from the controller processor 222 tothe PHY layer 210 or the upper layer. The controller processor 222 mayfurther include independent memory control logic or integrated memorycontrol logic for controlling the controller interface 221, the mainmemory 223, and the sub memory 224. The memory control logic may beimplemented to be included in the main memory 223 and the sub memory 224or may be implemented to be included in the controller processor 222.

Furthermore, each of the main memory 223 and the sub memory 224 may beconfigured to store a signal processed by the controller processor 222and may be configured to output the stored signal based on a requestfrom the controller processor 222. The main memory 223 may be a volatilememory (e.g., RAM) configured to temporarily store data required for theoperation of the controller processor 222. The sub memory 224 may be anon-volatile memory in which an operating system code (e.g., a kerneland a device driver) and an application program code for performing afunction of the controller 220 may he stored. A flash memory having ahigh processing speed, a hard disc drive (HDD), or a compact disc-readonly memory (CD-ROM) for large capacity data storage may be used as thenon-volatile memory. Typically, the controller processor 222 may includea logic circuit having at least one processing core. A core of anAdvanced RISC Machines (ARM) family or a core of an Atom family may beused as the controller processor 22.

A method performed by a communication node and a correspondingcounterpart communication node in a vehicle network will be describedbelow. Although the method (e.g., signal transmission or reception)performed by a first communication node, the method is applicable to asecond communication node that corresponds to the first communicationnode. In other words, when an operation of the first communication nodeis described, the second communication node corresponding thereto may beconfigured to perform an operation that corresponds to the operation ofthe first communication node. Additionally, when an operation of thesecond communication node is described, the first communication node maybe configured to perform an operation that corresponds to an operationof a switch.

FIG. 3 is a sequence chart illustrating an embodiment of an operationmethod of a communication node constituting an Ethernet-based vehiclenetwork.

A switch, a first end node, and a second end node shown in FIG. 3 mayconstitute the Ethernet-based vehicle network described with referenceto FIG. 1. Here, the switch may be a bridge. Further, each of theswitch, first end node, and second end node may have the structure ofthe communication node 200 described with reference to FIG. 2.

Referring to FIG. 3, the first end node may transmit a frame to theswitch (S300). On the other hand, the switch may have at least one portand may receive the frame from the first end node, for example, via afirst port among the at least one port.

Then, the switch may parse a header of the frame received from the firstend node (S301). The switch may check whether the frame is erroneous ornot (S302). Specifically, the switch may perform a cyclic redundancycheck (CRC) based on a frame check sequence (FCS) in a FCS fieldincluded in the received frame in order to check whether the frame iserroneous. That is, step S302 performed in the switch may refer to aprocess of checking integrity of the frame received from the first endnode. Here, the frame transmitted from the first end node to the switchmay be described with reference to FIG. 4.

FIG. 4 is a conceptual diagram illustrating an embodiment of a frameused in an Ethernet-based vehicle network.

Referring to FIG. 4, a frame 400 may include a physical layer (PRY)header, a medium access control layer (MAC) frame, and an FCS field 408.In particular, the PHY header may include a preamble 401 and a startframe delimiter (SFD) field 402. Also, the MAC frame may be locatedafter the SFD field 402. The MAC frame may include only a MAC header, ormay include the MAC header and a logical link control (LLC) frame. TheMAC header may include a destination address (DA) field 403, a sourceaddress (SA) field 404, and a length/type field 405. The DA field 403may include identification information (e.g., MAC address) of acommunication node receiving the corresponding MAC frame. The SA field404 may include identification information (e.g., a MAC address) of acommunication node transmitting the corresponding MAC frame.

The length/type field 405 may indicate the length of a data field 406 oran Ethernet type supported by the communication node transmitting theframe 400 based on the corresponding protocol. The LLC frame may includethe data field 406 and may further include a pad field 407 as needed(e.g., to meet the minimum MAC frame size). Here, the pad field 407 maybe added after the data field 406.

That is, referring again to FIG. 3, the switch may perform the CRC basedon the FCS included in the FCS field 408 of the frame described withreference to FIG. 4. Then, when it is determined that there is no errorin the received frame, the switch may obtain a destination MAC addressin the DA field of the frame (S303). Then, the switch may search for aport corresponding to the destination MAC address based on a routingtable (S304).

TABLE 1 MAC address Port aaaa.aaaa.aaaa 1 bbbb.bbbb.bbbb 2cccc.cccc.cccc 3 dddd.dddd.dddd 4 eeee.eeee.eeee 5

Table 1 is a table showing an embodiment of the routing table of theswitch. It may be assumed that the switch has five ports such as a firstport, a second port, a third port, a fourth port, and a fifth port. Inthis case, the switch may have a routing table as shown in Table 1above. That is, the routing table may be composed of a MAC address fieldand a port field. The MAC address field may include a MAC address of acommunication node connected to the switch, and the port field mayinclude information on a port mapped to the corresponding MAC address.

For example, the first port of the switch may be used to transmit andreceive frames to/from a communication node having a MAC address of(aaaa.aaaa.aaaa), and the second port of the switch may be used totransmit and receive frames to/from a communication node having a MACaddress of (bbbb.bbbb.bbbb).

Therefore, when the MAC address included in the DA field of the receivedframe is determined to be (aaaa.aaaa.aaaa) in the step S304, the switchmay search the routing table for the port corresponding to the MACaddress of (aaaa.aaaa.aaaa). In the above example, based on the routingtable, the switch may identify that the port corresponding to the MACaddress of (aaaa.aaaa.aaaa) is the first port. That is, the switch maysearch for the port corresponding to the destination MAC address amongat least one port it has based on the routing table.

Thereafter, the switch may transmit the frame to the second end nodethrough the searched port (S305). Accordingly, the second end node mayreceive the frame from the switch.

FIG. 5 is a sequence chart illustrating another embodiment of anoperation method of a communication node constituting an Ethernet-basedvehicle network.

A switch, a first end node, and a second end node shown in FIG. 5 mayconstitute the Ethernet-based vehicle network described with referenceto FIG. 1. Here, the switch may mean a bridge, and support a cut-throughframe routing scheme, the frame routing scheme specified in the IEEE802.1Qcc standard, Each of the switch, first end node, and second endnode may have the structure of the communication node 200 described withreference to FIG. 2.

Referring to FIG. 5, the first end node may transmit a frame to theswitch (S500). On the other hand, the switch may have at least one portand may receive the frame from the first end node, for example, via afirst port among the at least one port. Then, the switch may obtain adestination MAC address in a DA field of the received frame withoutchecking whether the frame received from the first end node is erroneous(S501).

Then, the switch may search for a port corresponding to the destinationMAC address based on the routing table (S502). Thereafter, the switchmay transmit the frame to the second end node through the searched port(S503). Accordingly, the second end node may receive the frame from theswitch.

Then, the second end node may check whether received frame is erroneousor not. The second end node may parse a header of the received frame andcheck whether the received frame is erroneous by performing a CRC basedon a FCS included in a FCS field of the received frame.

Then, when the received frame as no error, the second end node maydecode the received frame. The second end node may obtain data containedin the received frame through decoding of the received frame.Thereafter, the second end node may generate a frame indicating that theframe has been successfully received and transmit the generated frame tothe switch.

That is, according to the operation method described with reference toFIG. 5, the switch may obtain the destination MAC address of the framewithout performing a check on whether or not the frame received from thefirst end node has an error. Also, the switch may search a portcorresponding to the obtained destination MAC address based on therouting table, and transmit the frame to the second end node through thesearched port. Therefore, the switch may cause the frame to be routed toa wrong port due to a latent error in the destination MAC address of theframe.

FIG. 6 is a sequence chart illustrating an operation method of a firstcommunication node in an Ethernet-based vehicle network according to anembodiment of the present disclosure.

Referring to FIG. 6, a first communication node may be a switch or abridge. to addition, a first end node and a second end node shown inFIG. 6 may refer to communication nodes connected to the firstcommunication node. In the below description, the first communicationnode may be described as being a switch, for example. Also, the firstcommunication node may support the cut-through frame routing scheme,which is the frame routing scheme proposed in the IEEE 802.1Qccstandard.

The first end node may transmit a first frame to the switch (S600). Onthe other hand, the switch may have at least one port and may receivethe first frame from the first end node, for example, via a first portamong the at least one port.

Then, the switch may determine a port for transmitting the first framereceived from the first end node. For this, the switch may obtain adestination MAC address of the first frame (S601). Here, the switch mayobtain the destination MAC address included in a MAC header of the firstframe without checking whether the first frame is erroneous according tothe cut-through frame routing scheme.

Then, the switch may search for a port corresponding to the obtaineddestination MAC address of the first frame based on the routing table(S602). That is, the switch may identify a port corresponding to thedestination MAC address of the first frame among the at least one portof the switch based on the routing table.

When the port corresponding to the destination MAC address does notexist, the switch may generate a second frame including an indicatorindicating an occurrence of an error in the first frame. The error inthe first frame may indicate that there s an error in the destinationMAC address of the first frame. Here, the second frame may furtherinclude an indicator for instructing correction of the error for thefirst frame or an indicator for requesting transmission of anerror-corrected frame in which the error of the first frame iscorrected. In addition, the switch may generate an additional frame thatincludes the indicator instructing correction of the error for the firstframe or the indicator for requesting transmission of theerror-corrected frame for the first frame.

Then, the switch may transmit the generated second frame to the firstend node (S604). Here, the first end node may be a communication nodecorresponding to a source address of the first frame. That is, theswitch may transmit the second frame to a communication nodecorresponding to the MAC address included in the SA field of the firstframe.

Thereafter, the switch may discard the first frame (S605). However,embodiments according to the present disclosure are not limited todiscarding the first frame after the switch transmits the second frameto the first end node. That is, the switch may discard the first framebefore generating the second frame or before transmitting the secondframe to the first end node. For example, the time point at which thefirst frame is discarded in the switch may he preset to a time pointsuch as a time point when the error in the first frame is recognized, ora time point after a predetermined time from the time point at which theerror in the first frame is recognized.

Further, the switch may not operate in the cut-through type framerouting scheme after the error in the first frame occurs. That is, thecut-through frame routing scheme supported by the switch may be stopped.Therefore, the switch may check the frames received after the time atwhich the error of the first frame is recognized, and then obtain thedestination MAC addresses of the frames received after that withperforming error check operations on the received frames.

The first end node may receive the second frame from the switch inaccordance with the transmission S604 of the switch. The first end nodemay identify the occurrence of the error in the first frame through thereception of the second frame. Specifically, the first end node mayidentify the indicator included in the second frame, and may identifythe occurrence of the error in the first frame through the obtainedindicator. That is, the first end node may recognize that there is anerror in the destination MAC address of the first frame. Alternativelyor additionally, the first end node may receive, from the switch, aframe including the indicator for requesting transmission of the thirdframe obtained by correcting the error of the first frame.

After the first end node obtains the indicator for requestingtransmission of the third frame, the first end node may generate thethird frame in which the error of the first frame is corrected (S606).Here, the first end node may generate the third frame without receivingthe frame containing the indicator requesting the transmission of thethird frame from the switch.

Thereafter, the first end node may transmit the third frame to theswitch (S607). Thus, the switch may receive the third frame from thefirst end node. Then, the switch may perform a check on whether thethird frame is erroneous (S608). The switch may parse a header of thethird frame and check an error of the third frame by performing a CRCbased on a FCS included in a FCS field of the third frame.

Thereafter, the switch may obtain a destination MAC address included ina DA field of the third frame (S609). Then, the switch may search a portcorresponding to the destination MAC address of the third frame based onthe routing table (S610). Then, the switch may transmit the third frameto the second end node through the searched port (S611).

On the other hand, the second end node may receive the third frame fromthe switch. Then, the second end node may check whether or not the thirdframe is erroneous. The second end node may parse the header of thethird frame and perform a CRC based on the FCS included in the FCS fieldof the third frame.

When the second end node determines that there is no error in the thirdframe, the second end node may decode the third frame. That is, theswitch may obtain the data contained in the third frame through decodingof the third frame. Then, the second end node may generate a fourthframe indicating that the third frame has been successfully received andtransmit the fourth frame to the switch.

As described above, according to the operation method of the firstcommunication node described with reference to FIG. 6, when a routingerror of a received frame occurs due to an error of a destination MACaddress of the received frame, the switch supporting the cut-throughframe routing scheme may notify a communication node corresponding to asource address of the received frame that the destination MAC address ofthe frame has an error. In addition, the switch may stop the cut-throughframe routing scheme after the routing error of the frame occurs,perform checks on errors in frames received after the routing error ofthe frame occurs, and then perform the routing of the frames.

FIG. 7 is a sequence chart illustrating an operation method of a firstcommunication node in an Ethernet-based vehicle network according toanother embodiment of the present disclosure.

Referring to FIG. 7, a first communication node may be a switch or abridge. In addition, a first end node and a second end node shown inFIG. 7 may refer to communication nodes connected to the firstcommunication node. In the below description, the first communicationnode may be described as being a switch, for example. The firstcommunication node may support the cut-through frame routing scheme,which is the frame routing scheme proposed in the IEEE 802.1Qccstandard.

The first end node may transmit a first frame to the switch (S700). Onthe other hand, the switch may have at least one port and may receivethe first frame from the first end node, for example, via a first portamong the at least one port.

Then, the switch may determine a port for transmitting the first framereceived from the first end node. For this, the switch may obtain adestination MAC address of the first frame (S701). Here, the switch mayobtain the destination MAC address included in a MAC header of the firstframe without checking whether the first frame is erroneous.

Then, the switch may search for a port corresponding to the obtaineddestination MAC address of the first frame based on the routing table(S702). That is, the switch may identify a port corresponding to thedestination MAC address of the first frame among the at least one portof the switch based on the routing table.

When a port corresponding to the destination MAC address exists in therouting table, the switch may transmit the first frame to the second endnode through the corresponding port (S703). That is, the steps S700 toS703 performed by the switch may mean a routing process for determininga transmission path of the first frame.

For example, the switch may have a first port, a second port, and athird port, and may receive the first frame from the first end nodethrough the first port thereof. Then, the switch may search a portcorresponding to the destination MAC address of the first frame amongthe second port and the third port based on the routing table. Theswitch may then transmit the first frame to the second end node via thesecond port if the second port is identified as the port correspondingto the destination MAC address of the first frame.

The second end node may receive the first frame from the switch. Then,the second end node may check whether or not the first frame iserroneous (S704). Specifically, the second end node may perform a CRCbased on a FCS of a FCS field included in the first frame.

When it is determined that an error exists in the first frame, thesecond end node may generate a second frame including an indicatorindicating the occurrence of the error in the first frame (S705). Here,the occurrence of the error in the first frame may mean that there is anerror in the destination MAC address of the first frame and the firstframe has been transmitted to the second end node which is a wrongdestination.

Then, the second end node may transmit the generated second frame to theswitch (S706). Here, the second end node may transmit the second frameto a communication node corresponding to the MAC address included in theSA field of the first frame, that is, the communication nodecorresponding to the source address.

The switch may receive the second frame from the second end node. Then,the second frame may be transmitted to the first end node (S707). Here,the communication node corresponding to the source address of the firstframe may be the first end node. The second frame transmitted from theswitch and the second end node may indicate that there is an error inthe destination MAC address of the first frame. In addition, the switchmay further transmit a frame including an indicator requestingtransmission of an error-corrected frame in which the error in the firstframe is corrected. Additionally or alternatively, the switch mayfurther include an indicator in the second frame requesting transmissionof the error-corrected frame of the first frame.

Here, the second end node may generate a third frame including anindicator for instructing error checks of the frames received after that(S708). Thereafter, the second end node may transmit the generated thirdframe to the switch (S709). Here, the indicator for instructing theerror checks of the frames included in the third frame may be anindicator for requesting routing of frames after performing error checkson the frames transmitted from the switch. That is, it may have the samemeaning as requesting to stop the cut-through frame routing scheme,which is a current frame routing scheme of the switch.

The indicator for instructing the error checks on the frames may betransmitted as included in the second frame, instead of the third frame.In other words, the switch may not generate the third frame, but mayinclude the indicator in the second frame and transmit it to the switch.

On the other hand, the switch may receive the third frame from thesecond end node. Then, the switch may obtain the indicator included inthe received third frame, and may be informed by the obtained indicatorthat the cut-through frame routing scheme is requested to be stopped.Thus, the switch may perform error check operations on the framesreceived after the reception of the third frame.

On the other hand, the first end node may receive the second frame fromthe switch. The first end node may obtain the indicator included in thesecond frame and may identify the occurrence of the error in the firstframe through the obtained indicator. That is, the first end node mayrecognize that there is an error in the destination MAC address of thefirst frame.

Then, the first end node may receive the frame including the indicatorfor requesting transmission of the error-corrected frame of the firstframe from the switch. The first end node may obtain the indicatorincluded in the received frame, and may identify that a fourth frameshould be transmitted based on the obtained indicator. Thereafter, thefirst end node may generate the fourth frame in which the error of thefirst frame is corrected (S710).

Then, the first end node may transmit the fourth frame to the switch(S711). On the other hand, the switch may receive the fourth frame fromthe first end node. Then, the switch may check whether the fourth frameis erroneous (S712). The switch may parse a header of the fourth frameand check whether the fourth frame is erroneous by performing a CRCbased on a FCS included in a FCS field of the fourth frame.

Then, the switch may obtain a destination MAC address included in a DAfield of the fourth frame (S713). Then, the switch may search a portcorresponding to the destination MAC address of the fourth frame basedon the routing table (S714). Then, the switch may transmit the fourthframe to the second end node through the searched port (S715).

On the other hand, the second end node may receive the fourth frame fromthe switch. Then, the second end node may check whether or not thefourth frame is erroneous. The second end node may parse a header of thefourth frame and perform a CRC based on a FCS included in a FCS field ofthe fourth frame.

Thereafter, when the fourth frame has no error, the second end node maydecode the fourth frame. That is, the second end node may obtain dataincluded in the fourth frame through decoding of the fourth frame. Then,the second end node may generate a fifth frame indicating that thefourth frame has been successfully received and transmit it to theswitch.

As described above, according to the operation method of the firstcommunication node described with reference to FIG. 7, the switchsupporting the cut-through frame routing scheme in the vehicle networkmay transmit a frame to a communication node which is a wrongdestination due to a routing error of the frame caused by an error of adestination MAC address in the frame. Here, the switch may receive aframe indicating that the routing error of the frame has occurred fromthe communication node that has received the frame, and inform thecommunication node corresponding to a source address of the frame thatthere is an error in the destination MAC address of the frame. Inaddition, the switch may stop the cut-through scheme after the routingerror of the frame occurs, perform error checks on frames received afterthat, and then perform the routing of the frames.

The methods according to the embodiments of the present disclosure maybe implemented as program instructions executable by a variety ofcomputers and recorded on a computer readable medium. The computerreadable medium may include a program instruction, a data file, a datastructure, or a combination thereof. The program instructions recordedon the computer readable medium may be designed and configuredspecifically for the present disclosure or can be publicly known andavailable to those who are skilled in the field of computer software.

Examples of the computer readable medium may include a hardware devicesuch as ROM, RAM, and flash memory, which are specifically configured tostore and execute the program instructions. Examples of the programinstructions include machine codes made by, for example, a compiler, aswell as high-level language codes executable by a computer, using aninterpreter. The above exemplary hardware device can be configured tooperate as at least one software module in order to perform theoperation of the present disclosure, and vice versa.

While the embodiments of the present disclosure and their advantageshave been described in detail above, it should be understood thatvarious changes, substitutions and alterations may be made hereinwithout departing from the scope of the disclosure.

What is claimed is:
 1. An operation method of a first communication nodein an Ethernet-based vehicle network, the operation method comprising:receiving a first frame from a second communication node; obtaining adestination address of the first frame; and transmitting a second frameincluding an indicator for indicating an occurrence of an error in thefirst frame to a communication node corresponding to a source address ofthe first frame, when a port corresponding to the destination addressdoes not exist in a routing table.
 2. The operation method according toclaim 1, wherein the destination address is obtained from a mediumaccess control (MAC) header of the first frame.
 3. The operation methodaccording to claim 1, further comprising discarding the first frame. 4.The operation method according to claim 1, wherein the second framefurther includes an indicator for instructing correction of the error inthe first frame.
 5. The operation method according to claim 1, whereinthe second frame further includes an indicator for instructingtransmission of an error-corrected frame in which the error in the firstframe is corrected.
 6. The operation method according to claim 1,further comprising: receiving a third frame from the secondcommunication node; performing an error check operation on the thirdflame; obtaining a destination address of the third frame when the thirdframe has no error; and transmitting the third frame through a portcorresponding to the destination address of the third frame based on therouting table.
 7. The operation method according to claim 1, wherein thefirst communication node is a switch or a bridge, and wherein the secondcommunication node is an end node connected to the first communicationnode.
 8. The operation method according to claim 1, wherein the firstcommunication node supports a cut-through frame routing scheme.
 9. Anoperation method of a first communication node in an Ethernet-basedvehicle network, the operation method comprising: receiving a firstframe from a second communication node; obtaining a destination addressof the first frame; transmitting the first frame through a portcorresponding to the destination address based on a routing table of thefirst communication node; receiving a second frame including anindicator indicating an occurrence of an error in the first frame from athird communication node receiving the first frame; and transmitting thesecond frame to a communication node corresponding to a source addressof the first frame.
 10. The operation method according to claim 9,wherein the destination address is obtained from a medium access control(MAC) header of the first frame.
 11. The operation method according toclaim 9, wherein the second frame further includes an indicator forinstructing correction of the error in the first frame.
 12. Theoperation method according to claim 9, wherein the second frame furtherincludes an indicator for instructing transmission of an error-correctedframe in which the error in the first frame is corrected.
 13. Theoperation method according to claim 9, further comprising: receiving athird frame from the third communication node, the third frame includingan indicator requesting to perform an error check operation; receiving afourth frame from the second communication node; performing the errorcheck operation on the fourth frame; obtaining a destination address ofthe fourth frame when the fourth frame has no error; and transmittingthe fourth frame through a port corresponding to the destination addressof the fourth frame based on the routing table.
 14. The operation methodaccording to claim 9, wherein the first communication node is a switchor a bridge, and wherein the second communication node and the thirdcommunication node are end nodes connected to the first communicationnode.
 15. The operation method according to claim 9, wherein the firstcommunication node supports a cut-through frame routing scheme.
 16. Anoperation method of a first communication node in an Ethernet-basedvehicle network, the operation method comprising: receiving a firstframe from a second communication node; performing an error checkoperation on the first frame; generating a second frame including anindicator indicating an occurrence of an error in the first frame whenthe first frame has the error; and transmitting the second frame to acommunication node corresponding to a source address of the first frame.17. The operation method according to claim 16, wherein the first frameis a frame on which the second node does not perform the error checkoperation.
 18. The operation method according to claim 16, wherein theerror in the first frame is identified by performing a cyclic redundancycheck on the first frame based on a frame check sequence (FCS) includedin a FCS field of the first frame.
 19. The operation method according toclaim 16, further comprising: generating a third frame including anindicator requesting to perform the error check operation; andtransmitting the third frame to the second communication node.
 20. Theoperation method according to claim 16, wherein the first communicationnode is an end node connected to the second communication node, andwherein the second communication node is a switch or a bridge.